渤海湾盆地廊固凹陷地层水化学纵向分带性与油气富集

渤海湾盆地廊固凹陷地层水纵向上特征复杂,地层水化学动力带的分布具有明显分带性。通过对廊固凹陷固安-旧州、柳泉-曹家务和河西务构造带上地层水化学动力带纵向特征及其与流体封存箱、油气分布关系探讨认为,地层水化学动力带主要划分为地层水交替流畅带、地层水交替阻滞带、地层水交替迟缓带及3者频繁交替带。地层水交替阻滞带与流体封存箱相吻合,该带也是油气纵向上开始富集的层段;地层水交替迟缓带一般位于流体封存箱之下,是油气富集的区域;水化学动力带频繁交替部位,是地层水矿化度低值背景上的相对高值区域,有利于油气富集。 

RELATIONSHIPS BETWEEN FORMATION WATER VERTICAL ZONING AND OIL AND GAS ENRICHMENT IN LANGGU SAG OF THE BOHAIWAN BASIN

Formation water vertical characteristics are complex in Langgu sag,Jizhong depression.The vertical distributions of the formation water chemic and dynamical belts have obvious zoning features.According to the vertical characteristics of the formation water chemic and dynamical belts and the relations with fluid compartment and distribution of oil and gas in Gu'an-Jiuzhou,Liuquan-Caojiawu and Hexiwu tectonic belts,it is considered that formation water can be divided into four belts vertically.They are formation water alternate fluency belt,formation water alternate blocking belt,formation water alternate tardy belt and formation water frequency alternation belt.It is also considered that formation water alternate blocking belt tallies with fluid compartments and is the beginning segments of oil and gas enrichment.Meanwhile,formation water alernate tardy belt basically locates under the fluid compartment and it is the favorable area of oil and gas enrichment.Furthermore,the area with relatively high value of salinity in the lower salinity beckground is available to oil and gas enrichment.